Strange hesitation uphill part throttle
I have a 95 Taurus LX, 3.8L Automatic with 88,000 miles. It starts and runs fine, is great on the freeway and for grocery runs.
It has a strange problem - part throttle uphill the car hesitates and stumbles (or maybe the transmission is hunting / juddering?) - either way the effect is that the car feels like it is struggling to get uphill.
If I accelerate harder uphill (say 1/2 to 3/4 throttle) the problem disappears.
Normal driving it is very smooth and shifts great - for example on-ramp performance is very good.
I only got the car about 6 weeks ago, and according to the previous owner it has new plugs but this problem has been there for some time. I checked transmission fluid when the car was hot and it is reddish-brown, up to the correct level, and smells 'normal'. Someone said to me that I should check the IAC, MAF, PCV etc. but don't know how to check these.
Anyone have any suggestions?